A1 Refereed original research article in a scientific journal

Galaxy group-associated distances to very high energy gamma-ray emitting BL Lacs KUV 00311−1938 and S2 0109+22



Authors: Koljonen, Karri I. I.; Lindfors, Elina; Nilsson, Kari; Heinämäki, Pekka; Kotilainen, Jari

Publisher: Oxford University Press

Publication year: 2024

Journal: Monthly Notices of the Royal Astronomical Society

Journal name in source: Monthly Notices of the Royal Astronomical Society

Volume: 531

Issue: 4

First page : 5084

Last page: 5096

ISSN: 0035-8711

eISSN: 1365-2966

DOI: https://doi.org/10.1093/mnras/stae1512

Web address : https://doi.org/10.1093/mnras/stae1512

Self-archived copy’s web address: https://research.utu.fi/converis/portal/detail/Publication/457147080

Preprint address: https://arxiv.org/abs/2406.13786

Additional information: The VLT/FORS2 data analysed here are available at the European Southern Observatory Science Archive Facility (http://archive.eso.org). The Gemini data is available at the Gemini Observatory archive (https://archive.gemini.edu). The SDSS data is available at the SDSS website: https://www.sdss4.org. The simulation data produced as part of this work are available from the authors on request.


Abstract

Blazars constitute the most numerous source class in the known extragalactic population of very high energy (VHE) gamma-ray sources. However, determining their redshifts is often challenging due to weak or non-existent emission lines in their spectra. This study focuses on two BL Lacs, KUV 00311−1938 and S2 0109+22, where previous attempts at redshift determination have faced difficulties. By combining spectroscopic observations with photometric redshift estimates, we tentatively assign a redshift of z = 0.634 to KUV 00311−1938 and a likely redshift of z = 0.49 to S2 0109+22. Establishing redshift estimates for high-redshift blazars is crucial for understanding extragalactic VHE gamma-ray sources and their interactions with the surrounding Universe.

Key words: BL Lacertae objects: general – galaxies: distances and redshifts – galaxies: groups: general.


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Funding information in the publication: 
Research funded by European Research Council (101002352) | Academy of Finland (306531,317636,320045,346071)


Last updated on 2025-27-01 at 19:39